DE102017213505A1 - Method and apparatus for operating a braking system for a vehicle having at least two automated parking brakes - Google Patents

Abstract

The present invention relates to a method and a device for operating a brake system for a vehicle with at least two automated parking brakes, which are characterized in that at a defined error case of a device of the vehicle at least one of the parking brake is automatically controlled and is controlled such that by means of the controlled parking brake a defined change in direction of the vehicle is achieved.

Description

The present invention relates to a method and a device for operating a brake system for a vehicle with at least two automated parking brakes, which are characterized in that at a defined error case of a device of the vehicle at least one of the parking brake is automatically controlled and is controlled such that by means of the controlled parking brake a defined change in direction of the vehicle is achieved.

State of the art

From the prior art, for example, the patent application DE 10 2010 001 482 A1 known. This document relates to a method for controlling at least one electronically controlled parking brake device in a vehicle, in particular in a commercial vehicle, proposed, wherein the parking brake device is used depending on engine and / or transmission parameters in predetermined operating states of the vehicle supportive. The parking brake device can also support a so-called steering brakes. If, for example, by evaluating Raddrehzahlunterschieden a predetermined steering angle is detected, the automatic steering braking can be supported by the method by z. B. the inner wheels of the cornering are braked by the parking brake device.

Disclosure of the invention

Advantageously, however, allows the inventive method and apparatus independent steering of the vehicle by the parking brakes.

This is made possible according to the invention by the features specified in the independent claims. Further embodiments of the invention are the subject of dependent claims.

The inventive method for operating a brake system for a vehicle with at least two automated parking brakes, characterized in that at a defined error case of a device of the vehicle at least one of the parking brake is automatically controlled and is controlled such that by means of the controlled parking brake a defined change in direction Vehicle is achieved.

This is understood to mean that a change in direction of the vehicle in motion is achieved by means of the parking brake. The method is thus carried out when the vehicle is in use, in particular exceeds a certain speed. The change in direction of the moving vehicle is achieved essentially exclusively by means of the parking brake. The method for operating a brake system is to be understood in this sense as a method for controlling the parking brakes. The existing parking brakes can be controlled independently of each other. For example. the change in direction of the vehicle is achieved exclusively by the control of one of the existing parking brakes. The activation of the parking brake leads to activation and application of the parking brake. If the parking brake is actuated only on one side of the vehicle, this results in a torque around the vehicle's vertical axis. In this way, in turn, a steering of the vehicle can be obtained. For example. is activated with two existing parking brakes on the rear axle of a vehicle, only the parking brake on the left side. This one-sided closing of the parking brake leads to a turning of the vehicle in the direction of the closed parking brake, in this case to the left side. Of course, it is also conceivable that several parking brakes are controlled. For example. All parking brakes on one side of the vehicle are activated while the parking brakes on the other side of the vehicle remain deactivated. It is also conceivable that a different driving a plurality of parking brakes (also on different sides of the vehicle) takes place, especially if the vehicle is equipped on all wheels with parking brakes. Furthermore, it is also conceivable that only a defined selection - in the sense of a subset - of the existing parking brakes is controlled. That it will be driven to achieve the desired change in direction one or more parking brakes but not all existing parking brakes. Furthermore, it is pointed out that the method is used in the event of a detected error. As a defined error case of a device of the vehicle is, for example, the failure or a limitation of the steering system to understand.

Advantageously, the safety of the vehicle during operation can be increased by this method. For example. can be generated by the method, a redundant system, which provides for a steering failure in a further steering capability. This is particularly relevant for steer-by-wire systems. In addition, by the method and the inclusion of existing components, a cost-effective solution can be realized.

In an alternative embodiment, the method is characterized in that the automated parking brakes are controlled independently of each other.

This means that at least two of the automated parking brakes can be controlled independently of each other. This should not be understood as merely a time offset of the control, but actually a fundamentally different control. While, for example, a parking brake is actuated during an executed method, a second parking brake is not activated in this method. Of course, it can be provided that all existing parking brakes are controlled differently. This differentiated control can be automated. Depending on the present situation, error case and / or present driver request, for example, a suitable control of the respectively required parking brake and / or parking brakes can be carried out automatically.

In an advantageous embodiment, the method is characterized in that the control of the at least one parking brake takes place taking into account at least two signals.

This is understood to mean that a triggering of the parking brake for generating the desired change in direction does not take place directly and directly when an error is identified. Rather, the control takes place in an identified error case based on at least two other signals. In the event that the detection of a fault of a device of the vehicle already takes place on a defined signal, the actuation of the parking brake is based on at least three signals, i. the detected error case and two other signals .. Under control should be understood on the one hand, the activation in general. Furthermore, should be understood under control but also the targeted activation to obtain the desired change in direction of the vehicle. In this case, advantageously, a signal can be associated with the activation in general and a signal with the targeted activation to obtain the desired change in direction. The control of the parking brake, or possibly the parking brakes, can also be understood as operating the brake system. By adding further signals, relevant information is comprehensively taken into account in order to carry out a suitable activation. In this way, an unnecessary and / or erroneous activation of the method can advantageously be avoided.

In one possible embodiment, the method is characterized in that the control of the at least one parking brake is performed on the basis of at least two signals which are generated by the driver, in particular which are generated by the driver in each case by means of an input device.

This is understood to mean that the signals used for the automated control of the parking brake can be generated and influenced by the driver. This allows consideration of the driver's request in the context of the method.

In a preferred embodiment, the method is characterized in that the activation of the at least one parking brake takes place on the basis of an activation signal generated by the driver, wherein in particular the activation signal is a signal of an actuated parking brake switch.

This is understood to mean that a triggering of the parking brake for generating the desired change in direction does not take place directly and directly when an error is identified. Rather, the control takes place in an identified error case based on a so-called activation signal. Such an activation signal can be generated and influenced by the driver.

This allows consideration of the driver's request, when the driving maneuver to change the direction of travel to be initiated.

In an alternative development, the method is characterized in that the activation of the at least one parking brake takes place on the basis of a direction signal generated by the driver, wherein in particular the direction signal is a signal of an actuated flasher and / or a steering angle sensor and / or a left or right window regulator is.

This is understood to mean that a triggering of the parking brake for generating the desired change in direction does not take place directly and directly when an error is identified. Rather, the control takes place in an identified error case based on a so-called direction signal. Such a direction signal can be generated and influenced by the driver. This makes it possible to take account of the driver's desire, where the vehicle should be controlled in the driving maneuver to change the direction of travel. Here it is possible in many ways to provide an input option for the driver. In particular, existing input devices can be used. Advantageously, while an input device is defined, which has a differentiation to the left and right to allow the driver intuitively entering the desired direction of travel or direction change. For example. the flasher, the steering wheel, a steering joystick or the windows.

In an advantageous embodiment, the method is characterized in that the change in direction is defined so that a vehicle in motion is thereby brought out of a danger zone and / or into a safety zone.

This is understood to mean that the vehicle is brought out of the danger zone and / or into a safety area by means of the activation of the parking brake. For this purpose, an automated evaluation of the environment as well as the driving and traffic situation can take place. The entire driving maneuver can be implemented in the sense of a partially automated driving maneuver. In doing so, the vehicle autonomously evaluates the environment with existing sensors and carries out the driving maneuver automatically. The definition of the change of direction is thus made by the vehicle itself. Of course, it can also be provided that the driver is involved in the execution of the driving maneuver. For example. the vehicle based on the evaluation of the traffic situation forward the driver information, for example, when the activation of the maneuver should be started (ie the activation signals should be discontinued) and / or in which direction the maneuver should be executed (ie which direction signal to be discontinued should). Advantageously, by the defined change of the direction of travel of the vehicle from the danger zone out an increase in security are made possible.

In one possible embodiment, the method is characterized in that the change in direction is defined by a signal representing a driver request of a device of the vehicle, in particular by a signal of a flasher and / or a signal of a steering angle sensor.

By this is meant that the driver is involved in the execution of the driving maneuver. The driver determines the direction in which the vehicle should be steered when performing the maneuver. For this purpose, an input of the driver's request by means of a device of the vehicle. As a device of the vehicle can, for example, the flasher be understood. But also the steering wheel can serve as a means for entering the driver's request. In the first case, a signal of the flasher is recorded and evaluated, in the latter case, a signal of the steering angle sensor is recorded and evaluated. Advantageously, thereby the driver's request can be recorded and implemented. Due to the integration of already existing in the vehicle and the driver known input devices, intuitive operation can be enabled. Furthermore, this will require no additional components. This allows a cost-effective implementation.

In a preferred embodiment, the method is characterized in that the faulty device is a steering device and in particular the defined fault is a failure of the steering device.

This is understood to mean that the method is listed when the steering device has defects and / or failed. Decoupled steering systems, so-called steer-by-wire systems, have no direct connection between the steering wheel and the Radwinkelstellern on. A failure of a component can therefore have far-reaching consequences. By the presented method, however, for example, an emergency solution can be achieved for the emergency and furthermore a steering during an emergency stop can be made possible.

According to the invention, a brake system for a vehicle with at least two automated parking brakes and a control device for controlling the parking brakes is further provided, wherein the brake system is set up so that at least one parking brake is differentially controlled and characterized in that in a defined error case of a device of the vehicle the at least one parking brake can be controlled in such a way that by means of the at least one parking brake a defined change of direction of the vehicle in motion can be achieved.

According to the invention, a device is furthermore provided which is designed to carry out the described method when used as intended.

This is understood to mean that the device is designed, that is to say furnished, and / or has means, when used as intended, to carry out a method as described above. As a device, for example, a control device and / or a memory element and / or a control element can be considered. For example, an ESP control unit or APB control unit, which performs a control of a parking brake to achieve a defined change in direction a vehicle. In particular, a control device is provided, which is set up and configured to control a plurality of existing automated parking brakes of a vehicle independently of one another. By such devices, the advantages already described in the context of the method can be implemented.

According to the invention, a computer program is also provided, which is set up to carry out the described method and a machine-readable storage medium, on which the computer program is stored. This is understood to mean that the computer program has a program code for performing one or more or all of the above-mentioned method steps when the computer program is executed on a computer.

embodiments

It should be noted that the features listed individually in the description can be combined with one another in any technically meaningful manner and show further embodiments of the invention. Further features and expediency of the invention will become apparent from the description of embodiments with reference to the accompanying figures.

• 1 ein Bremssystem eines Kraftfahrzeugs in einer vereinfachten Darstellung,
• 2 eine Radbremse des Bremssystems in einer vereinfachten Schnittdarstellung, und
• 3 ein Verfahren in einer beispielhaften Ausführung.

From the figures shows:

• 1 a brake system of a motor vehicle in a simplified representation,
• 2 a wheel brake of the brake system in a simplified sectional view, and
• 3 a method in an exemplary embodiment.

1 shows in a simplified representation of a braking system 1 for a motor vehicle not shown in detail here. The brake system 1 has several wheel brakes 2 on, by a driver of the motor vehicle by a brake pedal device 3 can be actuated as service brakes. The wheel brakes 2 are denoted by LR, RF, LF and RR, which explains their position or assignment on the motor vehicle, where LR stands for the left rear, RF for the right front, LF for the left front and RR for the right rear. Between the brake pedal device 3 and the wheel brakes 2 are two brake circuits 4 and 5 formed, wherein the brake circuit 4 the wheel brakes LF and RR and the brake circuit 5 associated with the wheel brakes LR and RF. The two brake circuits 4 and 5 are identically constructed, so that the structure of both brake circuits 4 . 5 based on the brake circuit 4 will be explained in more detail below.

The brake circuit 4 is first with a master cylinder 6 the brake pedal device 3 connected, wherein the brake pedal device 3 also a driver-operable brake pedal 7 as well as a brake booster 8th having. The brake circuit 4 has a switching valve 9 ' and a high pressure switching valve 9 on, which are connected in parallel to each other and the master cylinder 6 consequences. The changeover valve 9 ' is normally open and allows a flow of the hydraulic medium of the brake circuit, so the brake fluid, in both directions. The high pressure switching valve 9 is formed normally closed and allows in the energized state, a flow of brake fluid only in the direction of the wheel brakes 2 , The changeover valve 9 ' is still with the two wheel brakes 2 with the interposition of one inlet valve 10 connected, which is designed to be normally open in both directions. The wheel brakes 2 the brake circuit 4 is also an outlet valve 11 assigned, which is formed normally closed. The exhaust valves 11 is a hydraulic pressure accumulator 12 downstream. On the outlet side are the exhaust valves 11 also with a suction side of a pump 13 connected, the pressure side between the switching valve 9 ' and the intake valves 10 with the brake circuit 4 connected is. The pump 13 is mechanical with an electric motor 14 coupled, the pump 13 and the electric motor 14 together a pressure generator 15 of the brake system 1 form. It is envisaged that the electric motor 14 the pumps 13 both brake circuits 4 and 5 assigned. Alternatively, it can also be provided that each brake circuit 4 . 5 its own electric motor 14 having.

Will the two changeover valves 9 ' the brake circuits 4 . 5 closed, the hydraulic pressure remains in the underlying section of the brake circuits 4 . 5 that is, between the changeover valves and the wheel brakes 2 Locked or maintained, even if the brake pedal 7 is relieved by the driver.

2 shows in a simplified sectional view of the embodiment of the wheel brakes 2 , The respective wheel brake 2 has a caliper 16 on which a brake disc 17 , which is rotatably connected to a wheel of the motor vehicle, embraces at their end faces. Each face of the brake disc 17 is a brake pad 18 the wheel brake 2 assigned. One of the brake pads 18 is on a front side of a slidable caliper 16 mounted brake piston 19 trained or arranged. The brake piston 19 has a cup-shaped structure in longitudinal section, so that it has a cavity 20 together with a recording 21 forms, in which the brake piston 19 is slidably mounted. The cavity 20 is fluidic with the inlet valve 10 connected, so if the inlet valve 10 and the switching valve 8th are open and the brake pedal 7 is actuated, the hydraulic pressure on the brake piston 19 acts against this against the brake disc 17 to shift, causing the brake disc 17 between the brake pads 18 the wheel brake 2 is clamped or jammed. Alternatively, by closing the switching valve 8th and driving the pressure generator 15 the hydraulic pressure is automated in the brake circuit 4 be generated. This is, for example, the case when the driver has a Button or switch operated to apply a parking brake on a grade.

The brake piston 19 is also an electromechanical actuator 22 associated with an electric motor 23 and one with the electric motor 23 Actively connected transmission 24 having. The gear 24 is designed as a spindle gear, the one with the electric motor 23 rotatably connected spindle 25 includes, as well as one in the brake piston 19 rotatably and on the spindle 25 longitudinally displaceably mounted spindle nut 26 , Will the spindle by the electric motor 23 driven, so it becomes the spindle nut 26 in the brake piston 19 displaced longitudinally. Here is the spindle nut 26 by the rotational movement of the spindle 25 so far displaced that they are connected to an axial stop 27 of the brake piston 19 in the room 20 meets, causing the brake piston 19 through the spindle nut 26 is taken. By controlling the actuator 22 is thus also a force on the brake piston 19 be applied to its displacement, which can be superimposed or superimposed with the force applied by the hydraulic pressure force. The control of the hydraulics as well as of the actuator 22 can through a control unit 18 respectively.

3 showed an exemplary embodiment of the method. The procedure starts with the step S1 , For example, with activation of the vehicle or when the vehicle over a certain speed. In one step S2 a check of defined functions is made. This can be done, for example, a check on the functionality of the steering device. The functionality check is carried out as long as the procedure is carried out. For example. A non-valid steering angle signal could be understood as a signal of a failure of the steering device. Upon detection of an error will be in a next step S3 determines whether a defined activation signal is present. For example. the driver can generate such an activation signal by pressing the parking brake button. Parallel to this, in a further step S4 determines whether a defined direction signal is present. For example. the driver can generate such a direction signal by operating the flasher.

Alternatively, a plausible signal of a steering angle sensor could be used as a direction signal, if this should be present. In the presence of a valid activation signal and a valid direction signal become in one step S5 evaluated the signals. According to the signals and their evaluation, the parking brake device is in one step S6 activated. The activation takes place, for example, as Zuspannung one of the existing parking brakes on the rear axle. As a result, a torque is generated about the vehicle vertical axis. This leads to influencing the direction of movement of the vehicle in the next step S7 , The process is done in one step S8 terminated when the vehicle has been brought to a safety area.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010001482 A1 [0002]

Claims (13)

Method for operating a brake system (1) for a vehicle with at least two automated parking brakes (29), characterized in that at a defined error case of a device of the vehicle at least one of the parking brakes (29) is automatically controlled and is controlled such that by means of triggered parking brake (29) a defined change in direction of the vehicle is achieved. Method according to Claim 1 , characterized in that the automated parking brakes (29) are controlled independently of each other. Method according to one of the preceding claims, characterized in that the activation of the at least one parking brake (29) taking into account at least two signals. Method according to one of the preceding claims, characterized in that the control of the at least one parking brake (29) on the basis of at least two signals, which are generated by the driver, in particular which are generated by the driver in each case by means of an input device. Method according to one of the preceding claims, characterized in that the activation of the at least one parking brake (29) takes place on the basis of an activation signal generated by the driver, wherein in particular the activation signal is a signal of an actuated parking brake switch. Method according to one of the preceding claims, characterized in that the activation of the at least one parking brake (29) takes place on the basis of a direction signal generated by the driver, wherein in particular the direction signal is a signal of an actuated flasher or a steering angle sensor. Method according to one of the preceding claims, characterized in that the change in direction is defined so that a vehicle in motion is thereby brought out of a danger zone and / or into a safety area. Method according to one of the preceding claims, characterized in that the change in direction is defined by a driver of a signal representing a device of the vehicle, in particular by - a signal of a flasher and / or - a signal of a steering angle sensor and / or - a signal of a left or right window regulator. Method according to one of the preceding claims, characterized in that the faulty device is a steering device and in particular the defined fault is a failure of the steering device. Braking system (1) for a vehicle with at least two automated parking brakes (29) and a control unit (28) for controlling the parking brakes (29), wherein the brake system (1) is set up so that at least one parking brake (29) can be controlled in a differentiated manner, characterized in that in a defined error case of a device of the vehicle, the at least one parking brake (29) is such automated controlled that by means of at least one parking brake (29) a defined change in direction of the moving vehicle can be achieved. Device (1, 2, 29, 28), which is set up, when used as intended, the method according to one of Claims 1 to 9 perform. Computer program adapted to operate as prescribed in one of the following when used as intended Claims 1 to 9 perform. Machine-readable storage medium on which the computer program is based Claim 12 is stored.

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